Kratometer



Dec- 10, 1929. H. @EMENT 1,738,986

KRATOMETER Filed June 18, 1926 5 Sheets-Sheet 1 INVENTOR JJM BY i

ATTORNEYS H. CLEMENT Dec. 10, 1929.

KRATOMETER Filed June 18, 192e 5 Sheets-Sheet 2 Juszslzlnznaxzn .1li OFIL. llllnL lllllllllll I llll nlll INVENTOR.

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A TTORNEY.

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Dec. 1o, 1929.

H. CLEMENT 1,738,986

KRATOMETER Filed June 18, 1926 5 Sheets-Sheet 3 IN VEN TOR.

B Y y ATTORNEYS DOC. 10, 14929. I H- CLEMENT I KRATOMETER A Filed June 18-, 1926 5 Sheets-Sheetl 5 fz AJzyr' -\RED 7/ zy//Z V Q l Y Qf-f ATTORNEYS HANS CLEMENT, OF NEW YORK, N. "1"., AESEG-NR TO GENERALCORPORATIGN F NEW YORK eyes of the pair.

Patented Dec. 10,'1929 rre smits PAT-ENT Ncritica OPTICAL C0., INC., A

y Knirroiunrnn Application filed .Tune 18,

`nosis were developed by which it Was gradually learned that there wasan interrelation of function between the intrinsic and extrinsic musclesand that in `many cases the eX- trinsic muscles Were mostly at fault.`At this time, terminatingwith the Work of llleyes, While diagnosis hadprogressed no satisfactory treatment had been developed. Frequentlytenotomy or the surgeons knife Was resorted to butthe results werecommonly disappointing. It Was beginning to be recognized that dynamicexercise and discipline of the extrinsic muscles of the eyes would bringabout the desired condition of orthophoria or balance and equilibriumiii the functioning,` of the muscles but at this time there was nosuitable apparatus for administering' such treatment and such efforts aswere made to accomplish this desired result did not meet with muchsuccess.

`This period of `gropingcame to an end (some thirty years ago) WhenHazen invented and put into successful use an apparatus, now known as akratometer, for exercising the ere trinsic muscles and thus innervaiinglthe deticieiit muscles so as to hiring about a con dition of balanceVand equilibrium of all of the muscles. Since then improvements intechnique of treatment and in the apparatus have been made. Morerecently `it has been found through experience and experiments that notv only is there an intimate interrelation or correlation in thefunctioning `of the intrinsic and extrinsic muscles of the eye but thatthere is also a similar interrelationland correlation of functioningofthe muscles between the tivo It `vvas foundthat the tivo eyes are notindividual entities but that the as a further development of eras i926.Serial No, 116,771.

pair must beponsidered asa single binocular instrument and deficienciescorrected .from that viewpoint; that the two eyesand their intrinsic andextrinsic muscles function `as one cOinpleteWhOle, the pair of eyes as asingle binocular optical apparatus and that efforts inust be madetowards establishing harmony and unity of action among all the parts ofthis single binocular apparatus, which when functioning properly`produces clear'single vision. However the apparatus as he etjoforcdeveloped makes no provision for this new understandinglof what isrequired although considerable ,advance has been made in the developmentof a simple technique in carrying forward Hazens Work.

The Hazen lratoiiieter employs the jump or step method of treatment,which has been found tofbe the lmost effective.

The present invention may be considered an improvement upon the Hazenlrratometer. An object of this invention is to provide a lratometerwhich will meet the needs arising' from the more recent discoveries inphysiologic-al Ophthalmology. This includes the diagnosis andinnervational treatment of the intrinsic and extrinsic muscles ofthetyvo eyes of the pair considered as one complete Whole, the pair of eyesbeing considered as a sinole binocular instrument or apparatus. So raras l am vaware such a kratoineter or apparatus has not heretofore beenproposed. Another object of the invention is to fill a demand for aninstrument, the necessity for Which has been long recognized, that willcn- `able the refractionist properly to care for the many'anomalouscases of eye strain that that not relieved by the prescription ofglasses. Another object is to provide a more effective apparatus forsuccessfully treating` the cause of those defects of ocular fmotilitythat produce eye strain, uncomfortable `vision, `poor vision, laclr ofequilibrium,`indi gestion, headache, slow focussing, and many othercomplaints. This includes increase in speed of operation in diagnosisand treatment so as not to fatigue the patient unduly; and

further includesthe embodying ,in the appa* ,tions from one strength tothe neXt in successive gradations of prism diopters one after the other,whereby thev effect on the yeye of one prism is not lost before the neXtprism can be brought into operating position. Another object is toproduce an apparatus by, which a more thorough and comprehensiveexamination can be made than heretofore was possible.v Another Objectisto produce an apparatus by which more eifective treatments may be giventhan heretofore.

" Another object is to provide an apparatus by innervational prismexercises.

means of which all eye defects coming under 'the generalheadof'imbalance may be successfullyV treated. Another object is toprovide a kratometer so built as to insure the heretofore unobtainablerigidity so essential in giving A further object isto provide animprovedkratometer which is compact, simple, light in weight,

v,and easy to operate, as well as neat and attractive in appearance.'V`'advantages will hereinafter appear.

Other; objects and The invent-ion includes various features ofconstruction and combinations of parts as will appear froml thefollowing description.'

VThe v lratometer illustrated in the accompanyingdrawings as oneembodiment Vof this invention Will'nowl be described after which n theinvention will be pointed out in claims, 'reference now being had to thedrawings 1n which: y Y

@,Fig. 1 is a front elevation of a complete kratometer emboc ying myinvention with the horizontal prism slides thereof in place;

Fig. 2 is an enlarged vertical section taken on the line 2 2 of Fig. 1;

Fig. 3 is'a similarly enlarged front elevationrof an end portion of oneof a pair of vertical prism slides forming partsof the completekratometer and which may take the place of the horizontal prism slidesshown in Fig. 1; Y y

Fig. 4 is an edge elevation of the saine partly brokeny out and partlyin central vertical section as viewed from the right in Fig. 3;

F ig'. 5 is a longitudinal vertical section, with parts in elevation, ofthe complete kratometer taken ontheline 5 5 of Fig. 1;

Fig 6 is a rear elevation of the complete kratometer with parts brokenaway;

' Fig. 7 Vis a partial vertical section in offset planes substantiallyas indicated by the zig- .zag'lineT-T of Fig. 8, the most of the partsappearing 4in Fig. 7 being at a higher level thanrthose shown-in Fig. 8;Y

. Fig'. 8 is anv enlargedl horizontal section ytakenvon the line 8 8 ofFig. 7

Fig.9 is an enlarged rear elevation of what appears in the upper part ofFig. 6, with some parts removed and with other parts broken away;

Fig. 10 is a horizontal transverse section on the line 1(1 10 of Fig. 9;

Fig. 11 is a detached front elevation of one of the rotatable batterydiscs, carrying auxiliary prisms, etc., and which is seen partly in rearelevation in Figs. 6 and 9 at the left;

Fig. 12 is an enlarged front elevation with the middle part broken outof the horizontal prism slide which appears at the right in Fig. r1;

Fig. 13 is an edge view of the same as viewed from the right in Fig. 12;

Fig. 14 is an enlarged front elevation of the det-ached holding bracketfor this slide and vhich is shown partly in broken lines at the right inFig. 1;

Fig. 15 is an edge view of the same as.

viewed from the right in Fig. 14.

Fig. 16 is a rear view of the same and as viewed from the right in Fig.15.

The mechanical construction as such which constitutes the illustratedembodiment of the invention will be first described with reference tothe drawings after which the operation lIy n that many details ofconstruction in the ex- Y empliiication of the invention shown in thedrawings may be departed from without thereby departing from the spiritof the invention. In order to enable a quick grasp and comprehension ofthe invention and of the construction shown in the drawings for carryingit out, a somewhat general description will now be given to be followedby a description in detail of the several parts and features which arecombined to form the complete coorganization which constitutes thekratom eter of my invention as a whole.

In the kratometer embodying my invention shown in the drawings two mainbatteries,

designated generally by A and B, are sup-i ported upon a triangular baseor main frame 1. These batteries are of a similar but reversedconstruction throughout, the battery A being for the right eye of thepatient while the battery B is for the left eye. The battery A isprovided with a sight aperture 2 for the right eye and the battery B isprovided with a sight aperture 3 for the left eye of the patient. Eachbattery contains a circular rotatable disc 4, these discs being alikeexcepting that they are of right and left construction together with allof the parts carried thereby. Each disc is provided with a circularseries of nine circumferentially equidistantly spaced auxiliariescomprising an open aperture 5, six supplemental prisms 6, 7, 8, 9, 10and 11, a Maddox rod 12 and a red glass 18. The prisms 6 to 11 inclusiveare respectively of three, five, ten, fifteen, twenty and twenty-fiveprism diopter strength.

, axis.

The three, five and ten diopter prisms G,

A7 and 8 and the Maddox rod 12 can be rotated in the disc l and may beset `at "any 'desired This rotative movement is accomplished by movingthe handle 14 of an axis latch which can be moved through a half circleor 1S o thereby to rotate these prisms and the Maddox rod through acomplete circle or 360o. The lever 15 of the axis latch Vforms a pointerand the base ofany one of these rou tatab'le prisms may lb'e thrown intothe desired position by setting the latch lever 15 opposite the wordsln, Out, Up `or Down which appear on a scale formed on the front side ofa stationary battery plate 1G which supports the othelrparts of thebattery. The Maddox rod `1 2 is so mounted in relation to its axis thatwhen the latch lever `lgpoints at Up or Down the line lof light seen bythe eye is vertical, and when the anis latch lever 15 is at lnfor Out7the line of light appears in the horizontal'position.

The fifteen, twenty andtwenty-iive diopter prisms 9, 10 and 11 are eachpermanently firmly set onthe rotatable disc 4in such posi tion that thebase of the prismwill always be outward from the nose ofthe patient withthe prism in register with lthe sight aperture 2 or 3, since this -isthe only position in which such strong "prisms can be used. The frontplate 16 near the top of the` battery is `provided with a sight opening17 in plain view from the operators ,position and through which he caneasily see the'indication on the rotatable disc el of the particularauxiliary thatis in position tobe in line with 'the sight aperture 2 or3. These indications are placed on the disc 4 one and one-half spaces inadvance of the auxiliary which is indicated -as is clearly shown in Fig.11, when this disc is rotated in the direction to increase the pi'smstrength froinprism to prism, it beip ioted that when rotated in thisorder the respective discs for the right and left eye tarn in oppositedirections.

Two pairs of prism-carrying slides, four separate slides in all, form afeature of the apparatus, two of these slidesbeing used at a time. Thetwo slides 18 are duplicates as are also the two slides 19. Eachprismslide 18 carries a series of thirteen horizontal prisms v2() firmlysecured thereon. The prism power ofthese prisms 2O ranges successivelyfrom one to thirteen diopters in one diopter intervals. An. openaperture 21 precedes the one diopter prism and a similar `open aperture22 succeeds the thirteen diopter prisms.

Each of the prism slides 19 carries a series of thirteen vertical prisms23 which in successive order range in'power from 0.25 diopters to 8.25diopters, in 0.25 diopter` steps,` these prisms beine rigidly fixed uponthe slide. Each of the prism `sli-des 19 has an open aperture241`p`recedingithe prism23iof the lowest power 'and a `similar opening25 s-ucceedingthe 'last or highest power prism.

Each of the prism slides is provided, as

shown, with an edge flange and upon the outer side of each of theseflanges upon each of the slides indications of the :prism powers aremarked, as shown in Eig. 13 for the slides 1S having the horizontal:prisms 20 and in Fig. 4 for the slides 1,9 having the vertical prisms23. The kind ofprisms in the slides, whether horizontal or vertical, andalso the position of the prism base and apex are indicated by a prismdiopter symbol marked upon the front of each end of each of the slides,as shown in the drawings in Figs. 1, 3 and 12.

The above described prism slides are for Eslide 18 or 19 is securely yetslidably held in" place at any position of sliding adjustmentcorresponding to the registering of its respective prisms with the`sight opening 2 or lby means of a spring pawl `27 to engage in Anotchesshown as formed in the forward edges ofthelslide flanges, this pawlbeing carried `by the bracket and shown as in theslform of a U-shapedleaf spring provided at its ends with inwardly projecting studs toengage i 1n the notches for-holding the slide-while permitting automaticdisengagement of these studsfrom the notches in theslide, to enabletheslide to have `unrestricted sliding movementin the bracket. Theprismpower of the prism ofthe slide `that is before the aperture can be notedby the operator in a convenient registeringopening 28 (Fig. 15) providedin the `lateral outer wall of the bracket 2G.

Each bracket 26 can be angled through an arc of 300 to the right or leftof the vertical position, thereby to angle the horizontal prism 20 awayfrom the horizontal position or the vert-icalprism 23 away from theverticalposition. .The exact horizontal or vertical position of therespective prisms 20 and is indicated when aline forming a marker ont'he'circular `base of the bracket 26 is in alignment with aline forminga marker on the "stationary front battery plate 16. A set screw l29inthe bracket 26 to be set up against `the front platel will hold thebracket and therefore its i prism slide rigidly at the desiredrangle, or`in the vertical position. YWhen the side to be angled awayfrom thevertical positionits set screw is loosened.

Hereinwhen the terms base in and base out areemployed reference is hadto the position I-of the-prism base in regard to `a versight one, ormore of which has a V -end forming a -yieldable pawl to engage in one oranother apertures 2- and 3 and therefore midway between the eyes of thepatient. VVith the prism slide 18, having thereon the horizontal prismsY 20, used together with vtheV supplemental prisms-6 to 11 inclusivecarried by the rotatable disc 4, any base in prism power from one toforty-six prism diopters, and any base out prism power from oneto'seventy-six prism 'diopters, can be quickly obtained. By using theprism slides 19 having thereon the verti- 'calprisms 23 in combinationwith the supplemental prisms 6 to 1l inclusive carried by lthe rotatabledisc 4, any desirable prism power base up or base down in quarterdiopter gradients may be quickly obtained.

The pupillary distance between the sight openings 2 and 3 may beadjusted from either side of theapparatus by rotating either one of twoknurled knobs 30, such adjustmentbeing vindicated by means of astationary pointer 3l and a movable scale 32 which is easily readfromthe operators position. Raising or lowering of thebatteries A and Bmay be accomplished from the operators end of the instrument byVrotating, a knurled handle i knob 33. Rigidity in position ofgthevertically adjusted batteries is maintained by means of a locking screw434 which should be loosened for adjustingl the'batteries vertically andtightenedV 4inmnediately thereafter. A

Achinrest 35 may be adjusted vertically by means of a knurled nutB, andmay also be adjustedhorizon'tally forward or back and heldby a setscrew- 37, thereby affording a eomfortablerest with the head of thepatient in correct'position. t

A stationary cover plate 38' at the rear of the rotatable disc 4 issecured at its ,center and its edgey to the front plate 16 in-spacedrelation therewith. This cover plate hassecuredthereto at its front orinner side a threearmed leaf spring 39 the radial arms of lwhich angleforwardly towards the disc 4 and each of whichcarries a forwardlyprojecting stud,

y equidistantly circumferentially spaced radialgrooves 40 formed in theladj acent vrear face of the rotatable disc 4, so that the, spring 89forms a latch for yieldingly of f y nine holdingthe rotatable disc 4 inadjusted position 'with any one of its nine auxiliaries in j line withthe sight opening Q or 3.

A trial case lens holder 4l is removably vsecured vupon the rear face ofthe cover plate 38. This lens holder provides three lens l.cells for thereception-of trial case lenses, a usual calibration 42vbeing provided onthe back of the cover plate 38. These rear cells arev made of the sizespecified when the instrumentiis ordered and are interchangeable kwithcells ofa different size. These rear lens cells are for the purpose oftrial case lens correction for any existing ametropia or presbyopia.

A trial lens holder providing three front lens cells is detachablymounted upon the bracket 26 at the front thereof and comprises twospaced semicircular plates 43 of which the outer plate is calibrated asshown and from the front of which three notched studs 44 projectoutwardly to the front. The plates 43 are provided as shown with twosets of screw holes either set of which may receive the screws whichhold in place the studs 44 and the spacers shown between the plates 43,thereby providing for the reception of either size of trial ease lensesnow commonly in use. These front lens cells are for the use ofcross-cylinder lenses in accommodation-convergence balance tests, andfor the addition of weak trial plus or minus spheres or cylinders inthis test, also for the reception of plus or minus spheres and loosejrisms, the use of which may be desirable while giving exercises. Tf thepatients prescription includes vertical prisms for consta-nt wear theirtrial case equivalents may be placed in these front lens cells duringexercises of the horizontal functions.

A horizontal forwardly and rearwardly extending rod 45 is provided tohold a test chart carrier 46. The chart holder 4G is free to slide alongthe entire length of this rod, which is calibrated both in inches andcentimeters. This rod is supported upon the base l at the front thereofand is mounted so that it may be raised or lowered or if desired it maybe entirely removed, a set screw 47 being provided for holding the rodat any desired height.i Test cards are provided in sufficient varietyfor the tests that are to be made and the exercises that are to be givenbut other test cards Amay be readily added or substituted in the chartholder 46. The chart holder 46 is-so made as to keep all the cards usedin near point. tests and exercises together, preserving them from lossand soiling and for maintaining them always ready for immediate use.

A stereoscope septum 48, for use in the treatment of suspenopsia andweak fusion, may be slid along and set at any needed place on the rod45. This septum is rotatable on a vertical axis and when in use it isturned to parallel the batteries. its purpose being to hide the rightside of the stereograph from the left eye of the patient, and the leftside of the stereograph will be hidden from the patients right eye. Vhennot in use this septum is turned to parallel the rod 45 and is slid upto the end of the rod next to 'the batteries where it cannot obstructthe patients vision.

A breath shield 49 is provided below each of the sight openings 2 and 3for protecting the prisms in the slides from the moisture llO sdescribed. For each of the batteries A and B the stationary front plate16 is centrally provided on its inner or rear side with a boss throughwhich passes a reduced forward portion ot a shouldered journal studwhich` is firmly secured in place on the plate 16 by means of a screw 51threaded into the reduced end of this stud. This stud 5() also has areduced rear end portion which is screwthreaded to receive thereon awasher-like nut 52. A screw 53, which is threaded into the end of thisreai1 reduced portion ot the stud 50, assists in firmly binding togetherthe rear cover plate 38, the stud 50 and the front plate 16.

A large spur gear 54 is journaled on the middleenlarged port-ion of thestud 50, this gear being maintained in place on the stud by the nut 52.At its rear side this gear 54 is shouldered to form a bearing for therotate able disc 4, which is annular and which 4is retained in place 0nthe shoulder of this gear by means oi a narrow ring 55 which is securedto the gear by means of small screws as shown in Figs. 2, 9 and 10. Therotatable auxiliary prisms 6, 7 and 8 and the rotatable Maddox rod 12are each firmly secured, respectively, in a rotatable holder 56journaled in the rotatable carrier disc 4 and each ot these holders 56carries a small spur gear 57 which is oi' one-halt the diameter ot thelarge spur gear 54 with which it meshes. The latch lever 15 is ot' bentshape and extends inwardly through an arcuate slot 58 in the iront plate16 and at itsinner end is lirmly secured to the large gear 54, the slot58 being somewhat more than 180o in length. The l `tch lever l5 at itsouter end carries a small pointer as shown and this latch lever is pro.vided with a slidable latch bolt" 59, to which the lever handle 14- issecured. This latch bolt is spring-pressed inwardly for having at itsinner end latching engagement with notches in the radially youter edgeof arcuate rib 60 on the front of the plate 16, these notches in the rib60 being positioned directly radially inward fromthe hereinbeforementioned scale indications Out, Up, cFlu, Down, Out, respectively.

It will be seen that when the latch lever 15 is roclred by means of itshandle 14, the tour small gears 57, together with the rotatable holders56 and the auxiliaries carried thereby, will be rotated at twice theangular' rate of movement of the latch lever 15, with the rotatable disc4 held stationary by its spring latch 39. When the latch lever 15 isheld stationaryby its bolt 59 and the disc 4 is rotated it will befnotedthat the rotatable auxiliaries 6, 7, 8 and 12 will also then be rotatedby reason ot their planetary travel around the then stationary centralgear 54, and this rotation ot these auxiliaries will result in bringingany one ot' them desired tor use into thecorrect position in alignmentwith the sight opening 2 or 3, the rotative position ot such auxiliarybeing determined by theposition ot adjustment oi4 the latch lever 15along the arcuate rib 60.

The slide-holding bracket 26 is provided at each of its tour cornerswith a small guide roller 61 to be engaged by t-he lateral flanges oftheprism-carrying slides 18 and 19, to facilitate the free and easymovement of these slides through the bracket in successively bringingthe prisms into alignment with the sight openingl 2 or 3. At its backthe slide 26 has a circular shoulder by which it is journaled in thetrout plate 16 and upon the rear tace of this shoulder there is securedan annular plate 62 which, at diametral point-s on its periphery, isprovided with projecting radial lugs, as shown, for passing throughnotches 63 provided in the front plate 16, thereby rendering the entirebracket 26 readily removable and replaceable merely by rotating thisbracket in its bearing through an angle ot 900, as will be clear fromthe drawings.

Each front battery plate 16 is secured, by means of a lug at the bottomthereof, upon the upper end ot au upstanding lateral arm 64, the lowerend of which is mounted to slide laterally upon a pair ot horizontalrods 65 which are rigidly carried by and project oppositely from a head66. A horizontal screw 67 is provided towards one end with right-handthreads and towards the other end with lett-hand threads and isjournaled in the head 66 in which it is rotatably held in place by meansof a screw stud 68, the inner end oit which is shaped to engage in acircumferential groove in the screw 67 at the middle of its length. Theright and lett hand screw 67 is positioned between the guide rods 65 andhas screw-threaded engagement with the battery-carrying arms 64.` rlhelinurled knobs 30 are fixed respectively upon the outer ends of t-hescrew 67 and by rotating either the one or the other of these knobs itwill be seen that pupillary adjustment` ot the batteries A and B may beellected. The pointer 31 tor indicating the pupillary distance is linedupon the front tace oi the head 66 and the movable scale 32 with whichthispointer cooperates is fixed at one oit its ends upon the iront faceof the right-hand battery-supporting arm 64. The breath shields 49 arerespectively supported by means oi: a stem 69 which is removablyreceived into a socket 69a shown as provided on the front tace ot thedownward projection on the iront battery plate 16 by which it isattached to the arm 64.

The chin rest 35 is slidable forward and back on a short horizontal bar70 upon which it is held adjusted posi tion by the set screw 37. The bar70 forms aT-head upon the upper end of a vertical screw 71 which ismountedto have sliding movement through a pair of spaced lugs whichproject from the rear of the head 66 and between which the adjusting nut36 is located upon the screw 71 with which it has screw-threadedengagementfor adjusting the height of the chin rest 85.1The uppermost ofthese lugs is provided i', with a screw 71 the inner end of whichengages inalongitudinal slot 71') in the screw 71, to prevent rotativemovement of the` chin rest (Figs. 5, 6 and 7 The lower one of these lugscarriesV a downwardly extending covertube 72 for the lower portion ofthe i downwardly extending adjusting screw 71.

The head 66 is fixed upon the upper end of a tubular stem r7 3 which isguided for vertical sliding movement in a collar 74 fixed in theupperend of atubular standard on the basel at the rear thereof, thestem7 3 being provided with flats as shown in Fig. 8, to prevent itsrotative movement in the collar 74 f and standard. The tubular stem 73has there- ,in a rotatable adjusting screw.7 5 which has screw-threadedengagement in the lower portion of the stem 7 3 and has fixed upon thelower end thereof a bevel pinion 76 which forms a journal for thescrew 73 in the basev 1 and also abuts against the vlatter to prevent upwardmovement of this'screw, as well as the stem 73 and all of the partscarried thereby, including the batteries A and B. The

, handle knob thereby thebatteries A and B will be verticallyv adjusted.The locking s crew134 is screw-threaded intolthe left side i of thestandard'in which the tubular batterysupporting stem 7 3 slides and atits inner end engages one ofthe flats on this vstem thereby` firmlytoclamp and hold this stem'against any looseness. i Y

The test chartholder 46 is of substantially YL-shape and has split'rings80 for removably and replaceably holding'thetest cards, which maybe'readily-raised or V lowered as desired. The holder 46 also includes amounting block 8l provided with a sleeve tovslide on the horizontal rod45, which 'is of angular cross-sed tion, shown as square, topi-eventlateral tipping ofthe holder Y46.. TheY septum'48 has a downwardlyYextending stem 82, which is pivotally'mountedron a vertical axis'on asleeve 83 which is' slidable along the horizontal rod 45.

The horizontal rod is supported at its ends upon and in spaced relationto a lower parallel rod 84 which at a point intermediate of its lengthis fixed in a T-head 85, in the construction shown extending fartherforward, together with the rod 45, from this head 85 than it extends tothe rear, the forward portions of these rods 45 and 84 being broken outin the drawings for lack of space. The T- head 85 is rigidly fixed uponthe upper end of a downwardly extending stem 86 slidably guided in a capcollar 87 which is firmly fixed upon and extends above the upper end ofa vertical Atube 88the lower end of which is rigidly fixed in thebase 1. The collar 87 is provided with an internal lug to engage in alongitudinal groove shown in the stem 86, for thereby preventingrotative movement of the stem 86 and the parts carried thereby. The setscrew 47, which screws through the collar 87 and tube 88, serves firmlyto clamp the stem 86 against looseness as well as to hold this stem inthe desired position of vertical adjustment, when it is desired to raiseor lower the test chart holder 46.

Perhaps some further explanation as to the operation of' the improvedkratometer forming the subject of this invention should be added. Itshould be understood that the prism slides 18 and 19 may be so placed intheir holders 26 and so moved therein as to obtain, in combination withthe auxiliary prisms carried by the rotatable discs 4, any prism powerefl'ect that may be required, base out, base in, base down, or base up.In the drawings (Figs. 1, 5 and 6) for clearness of illustration thetwoslides are shown at their lowermost position, however, in using thisimproved kratometer for obtaining similar results for the two eyes ofthe patient, one of the prism slides would extend downward while theother would extend upward from their respective holders 26 at thebeginning of an eye examination or an innervational exercise treatment,so that these slides may be moved in opposite directions either up ordown, one by the right hand and the other by the left hand of theoperator. The two eyes of the patient may be either tested or treated,both eyes at the same time, and the two slides may be movedsimultaneously. The effective prism power at any one time may be eitherthe sum of o1` the difference between the prism powers of a prism in theslide and a cooperating prism carried by the rotatable disc 4.

The patient is seated comfortably on a stool at the rear end of thekratometer which may restupon a convenient support such as a table.Proper adjustments are made as to the height of the batteries A and B,of the correct pupillary distance between the sight openings thereof 2and 3, and proper adjustment is messes made of the chin rest 35. Also,for near point or convergence work, the chart holder lo is adjusted tothe proper height and to the desired distance along the calibrated rod45, the steroscope septum d8, if used, being` set to the properposition. For distance worlr, in which the lines ot' sight in a pair ofnormal eyes would be parallel. the chart holder lo is adjusted downwardbelow the plane of vision. In the drawings (Figs. l, 6 and 9) thepupillary distance between the sight apertures 2 and 3 is shown at th-enarrowest, with the inner edges of the battery plates lo abutting; eachother, thereby to save space.

The operator sits at the front end ot the kratometer and somewhat to oneside thereof with his right hand positioned below the right-hand batteryB, to push the right-hand slide up yor pull it down, while his left handis positioned above the lett-hand battery A. for

pushing the lett-hand slide down or pulling; it up. The slides may bejumped quickly from a prism oi any one power to the next with anydesired interval between the jumps, for example, the slidesmay be thussucces` sively jumped from the prisms of low power to the prisms of highpower, or vice versa.

lf'he rotatable prism-carrying discs 4 may be operated in similar mannerlor changing "the prism powers. With these discs the prism power isincreased by moving the top of the disc outward, i. e., away from thenose o? the patient. For accomplishing this result mosteasily theoperator should rest his hands on the battery edges with the foreiinpjerextended along the lniurled edge oi' the rotary disc, when a quiclrdrawing in ot this iingrer will rotate the disc to the next higher prismpower. In turning the disc in the op posit@ direction, to reduce theprism power, the linger is bent and. a quick shove or straightening ofthe .linger pushes the oise over to the next lower prism.

llfhen prism power base in is desired this may be obtained by rotating,rthe discs fi to bring); in a prism power ci? tive or ten prism diopters,hase in, and then neutralizing this with 'live or ten prism diopters,base out, on 'the slides. then the power may be reduced step by step.l/Vith this manner oi op eration the effective base in prism power be'fore the sight aperture will be the diijlerence between the prismpowers ot the roti.. 1v d and the pr r of t have to be withdrawn andreset.

ict that the prism do not 'l lt will be evident that the number of`prism power combinations obtainable is large, and the arism powers maybe quickly shined by steps other.

Among; the numerous tests -liatmay be made with this improvedliratoineter the folor jumps troni one to any lowing may be noted:Phoria tests, for deteru mining,` `esophoria, enophoria, hyperphoria,

slides. rlhis saves time by.

or cyclophoria, including distance and convergence tests, and horizontaland vertical tests, the horizontal tests including the abduction and theadduction tests. Also, when required, the llladdoir rod may be used incombination with the prisms on the slides. The horizontal phoria testsapply in cases of suspenopsia and suppression. and the vertical duction.tests also apply in cases of suspenopsia. Also test-s may be made as tostereoscopic vision.

For these and other eye deficiencies the proper dynamic exercises may begiven with this improved lrratometer it'or successfully obtaining. inamuch shorter space of time than heretofore, the desired normal conditionof orthophoria and cminetropia. Exercises may be given tor suspenopsiaand suppression, for increasing convergence relaxation, ior convergenceinsufficiency, for developinpr amplitudes and association ofaccommodation and convergence, 'for the restoration oiE binocularJunctions, in motility andspeed of adiustnu-nt in various positions, forthe treatmentyperphcria, for develoigiing fusional sense and desire, forthe correction of squint, for sectional astigmatism, for obliqueastigina 'sin toi-sions and cyclophoria, for am blyopia er; anopsia,etc.

The lrratcmeter, based on principles discovered through experience andesperiments, opened an important iield which has gradually widened. llosingle apparatus has :unioni-'ed that reveals so many of theidioncracics ot a iioorly 'functioning pair of eyes, nor which is soeilective in moving; eye deliri ncies. It has been found that acuity ety sion develops more rapidly under ltratometer innervatinp,l impulsesthan by any other method of treatment known. The iniiproved kratoineterof the present in- .tion brings this important ophthalmocal apparet intolire with the advances `in the sci nce ot Ophthalmology thereby to .tillthe pi cnt need and requirements. For lnrther initier.. ration on thegeneral sub- `crence may be had to the following Qcular lrientatifiin7by Hazen; i ocular Balance, by Peckham; also other oublications.

The hratometer of' the first instrinnen principles controlli.. functionsoil ocular ve and binocular le vision. iliis' instrument makes possiblethe correct .griios's of many 'pnzsling phenomena lea dto ocularimbalance and strain,` whose gin and ii aretz ion were impossible by theolder instruments and methods. It. has been found that the methods oiinnervational exercisin made available with this 'inproved lratometersuccessfully correct many of these detects,givin@ comiort to manysui'ilerers for whom .ionsly nothing could bedone,

he present invention is to utilize the physiologic Cit ion

iso

and that in those'milder forms of imbalance which have been successfullytreated by the older methods, these improved liatometer methods shortenby more than halt the time spent in establishing balance.

Itis obvious that various modiications may be made in the constructionshown in .the drawings andV above particularly described, within theprinciple and scope of the invention yas defined in the appended claims.

I claim: 1. An ophthalmological apparatus having, in combination, a pairof stationary members rigidly supported in substantially horizontalrelation,ra pair of slides one of which isguided on each said member andeach slide carrying a ylongitudinal series of prisms any one of whichmay be brought into the line ofsight ot theveye at that side, a pair ofindependently krotatable discs each mountl ed upon one of said membersand carrying an arcuate series of prisms any one of which may be broughtint-o the line of sight to cooperate vvith one of the prisms in theslide, a baserforming a rigid frame upon which said members are rigidlymounted, a substantially horizontal rod rigidly mounted on the basetrame at the front of said members in zi-'vertical plane extendingbetween the lines of sight provided by said'inembers, and a chart holderprojecting above and slidable ot sight ofthe eye at that side, a pair ofindependently rotatable discs each mounted upon one o't said members andcarrying an arcuate series of prisms any one of which maybe brought intothe line of sight to cooperate With one of the prisms in the slide,

base forming a rigid frame upon which along said horizontalrod betweensaid meme Q5.;

sai d members are rigidly mounted, a substantially horizontal rodrigidly mounted on the v-aseframeatlthe,front of said members in a,vertical plane He'dtending `between the lines 'otsight provided by saidmembers, a chart holder projecting abeve and slidable along saidfro'd.,vand a stereoscope septum slidable bers and said chart holder.Y

3. An ophthalmological apparatus having,

lin, combination, a vpair of stationary members rigidly supported insubstantially hor` izontal'relation, apair ot slides one of which.is-guided on eachy said membery and each `slidecarryi'ng alongitudinal' series of prisms any one of which may be broughtinto theline of sight of the eye at that side, a pair of independently rotatablediscs each mounted Vupon one of said members 'and `carrying an arcuateseries ot prisms any one of which may be brought into the line of' sightto cooperate with one ot the prisms in the slide. a base forming a rigidiframe upon which `said members are rigidly mounted, a substantiallyhorizontal rod rigidly mounted on the base traine at the front of saidmembers in a vertical plane extending between the lines of sightprovided by said members, a chart holder projecting above and slidablcalong said rod, and means providing for the vertical adjustment of saidhorizontal rod relatively to said members.

4. An ophthalmological apparatus having,

, in combination, a support, a slide guided on the support carrying alongitudinal series ot' prisms progressively increasing in prism powerthrough the series and any one oi which may be brought into the line ofsight, a rotatable disc mounted on the support car rying an arcuateseries ot prisms progressively increasing in prism power through theseries and any one of which may be brought into the liiie ot' sight tocooperate with one ot the prisms in the slide, means for mounting atleast one of said prisms on the disc to provide for its axial rotativemovement thereon, and means tor axially rotating and setting this prismto any one of t'onr ditlerent axial positions on the disc at the line otsight and relatively thereto, viz, base out, base in, base down, baseup.

5. An ophthalmological apparatus having, incombination, a support, aslide guided on the support carrying a longitudinal series ot prismsprogressively increasing in prism power through the series and any oneof which may be brought into the line oi sight, a rotatable disc mountedon the support carrying an arcuate series of prisms progressivelyincreasing in prism power through the series and any one of which may bebrought into the line of sight to cooperate with one oi the prisms inthe slide, means for mounting a ploi'ality ot the prisms ot lower poweron the disc to provide i'or their axial rotative .noveinent thereon, andmeans for coneomitantly axially rotating these prisms in unison in thesaine direction at the same rate and setting them to any one of fourdii:- erent positions on the disc, viz, base out,

, base in, base down, base up, at the line ot sight and relativelythereto.

6. An oplithalniological apparatus having, in combination, a rigidlysupported stationary plate provided with a sight opening, a

Vslide guided on the plate provided with a longitudinal series oiequidistantly spaced sight apertures any one of which may be broughtinto line with the sight opening in the plate, a series of successiveprisms progressively increasing in power throughout the series rigidlyniount-ed on the slide Yso as to leave only the end apertures open andto cover all the others, a rotatable disc journaled on the plateprovided with a complete circumferential series of equidistantly spacedsight apertures any one of which may be brought into line with the sightopening in the plate, and auxiliar i optical elements mounted on thedisc to cover all its apertures save. one lett open, said elementscomprising a series oir' successive prisms progressively increasing inpower throiilgliout the series followed by a lvladdox rod and a redglass.

i". itin ophthalmological apparatus having, in combination, a rigidlysupported stationary plate provided with a sight opening, a slide guidedon the plate provided with a longitudinal series of equidistantly spacedsight apertures any one of which may be brought into line with the sightopening in the plate, a series ot successive prisms progressivelyincreasing in power throughout the series rigidly mounted on the slideso as to leave only the end apertures open and to cover all the others,a rotatable disc journaled on the plate provided with a completecircumferential series oi" equidistantly spaced sight fr ajiertures anyone of which may be brought into line with the sight opening in theplate, aiuriliary optical elements mounted on the disc to cover all itsapertures save one lett open, said elements comprising a series of fsuccessive prisms progressively increasing in power throughout theseries followed by a liladdoir rod and a red glass, means formounting aplurality of the successive low power prisnis and the Maddox rod toprovide for their axial rotation on the disc, and means torconcomitantly axially rotating these same direction at the same rate andsetthem to tour diliferent positions when i any one ot them is in linewith the sight opening in the plate, vie', with the prisms base out,base in, e down, base up, relatively to said sight opening, and with theMaddox rod having vertical. positions and horizontal positionsn tl., ilopththalmological apparatus having, in combination, a support, arotatable disc mounted. on the support carrying an arcuate ot prismsprogressively increasing in prism power through the series and any oneot' which may be brought into the line oit sight,4

a slide guided on the support carrying a longi- Vnal series ot prismsprogressively increasing in prism power through the series and amv oneoit which may be brought into the line j t to cooperate with a prism ont-he ro e disc, a trial case lens holder carried l support adjacent theline ot sight outwardly trom said disc, and another trial case lensholder carried by said support adjacent the line ot sight outwardly tromthe slide.

9. An ophthalmological apparatus having, in combination, a pair ofstationary members rigidly supported in substantially horizontalrelation, a pair of slides one of which is guided on each of saidmembers and each slide carrying a longitudinal series ot prismsprogressively increasing in prism power through the series and any oneoi which may be brought into the line ot sight ot' the eye at 4thatside, a pair of independently rotatable discs each mounted upon one otsaid members and carrying an arcuate series of prisms progressivelyincreasing in prism power' through the series and any one of which may ebrought into the line of sight to cooperate with one of the prismsin theslide, a pair of trial case lens holders one oit which is carried byeach of said members outwardly from the slide adjacent the liner oisight,4 and another pair of trial case lens holders one of which iscarried by each ot said members outwardly from said disc adjacent theline of sight.

l0. An ophthalmological apparatus having, in combination, a pair ofstationary members rigidly supported in substantially horizontalrelation, a pair of slides one ot' which is guided on each said memberand each slide carrying a longitudinal series of prisms any one of whichmay be brought into the line otsight of the eye at that side, a pairoli' independently rotatable discs each mounted upon one of said membersand carrying an arcuate Series of prisms any one ot which may be broughtinto the line oi sight to cooperate with one of' the prisms in theslide, a base forming a rigid frame upon which said inembers are rigidlymounted, a substantially horizontal rod rigidly mounted on the baseframe at the front of said members in a vertie cal pla-.ne extendingbetween the lines of sight provided by said members, a chart holderprojecting above and slidable along said rod, and a stereoscope septumrotatable on a vertical axis and slidable along said horizontal. rodbetween said members and said chart hold 1l. An ophthalmologicalapparatus han ing, in combination, a rigidly supported stationary plateprovided with a. sight opening, a slide rigidly carrying a longitudinalseries of prisms, a guide tor the slide pivotally mounted on the plateon an airis coincident with the siglitopening, releasable means forholding the slide at dilerent angular positions, and a rotatable discjournaled on the plate` carrying an arcuate series ot prisms any one oi`which may be brought into line with the sight opening to cooperate withone of the prisms carried by the slide.

12. An ophthalmological apparatus having, in combination, a support, aslide rigidly carrying a longitudinal series ot' prisms with their basesand apices respectively adj accntly directed on parallel linestransverse to the slide, another slide rigidly carrying a longitudinalseries ot prisms with their bases and apices directed respectivelytowards the opposite ends of the slide on the same line, means forinterchangeably mounting the leo slides on said support for slidingmovement to bring any prism into the line of sight, a rotatable discmounted on thesupport carry-l ;.ing an arcuate'series of prisms any onepi Which may be brought into the line of sight to cooperate with one vofthe prisms carried by one of the slides, and means providing forsettingneach of aplurality of the prisms on the disc to different axialpositions relatively to the line of sight so as thereby to cooperateAWith the prisms on the respective slides.

13. An ophthalmological apparatus having, in combination, a pair ofstationary .members rigidly supported in substantially horizontalrelation, a pair of slides guided respectively :tor sliding movement onsaid members and each slide carrying a longitudinal series of prisms anyone of which may be brought into the line of sight of the eye at thatside, a pair oit-independently rotatable discs mounted respectively uponsaid members and each carrying an arcuate series of prisms any oneofwhich may be brought into s the line of sight to cooperate With oneofthe Y of the line of sight provided by said members through said prisms.Y s

14. An ophthalmological apparatus having, .in combination, apair ofstationary members vrigidly supported in substantially horizontal.relation, a pair of slides guided respectively for sliding movement onsaid v members and each slide carrying a longitudinal series of prismsany one of which may be brought into the line of sight ofthe eye-at thatside, a pair of independently rotatable discs mounted respectively uponsaid members and each carrying an arcuater-seriesof prisms any one ofwhich may be brought into thetline ofsight to cooperate With oneot theprismsintheslide, a baseforming a rigid frame provided With a standard,a head rigidly carried by the top 'of the standard, a pair 'of lateralarms rigidly Vupstanding from the head and'upon the upper ends of Whichsaid membersrespectively are rigidly carried, andV a Achinrest'mount'edon the `head for both vertical and horizontal forward andback adjustment.

V15.v The invention defined in claim 13, vin combination with meansproviding forl the vertical adjustment relatively to the base oi saidhead together with the parts carried thereby, anda chin rest mounted onthe head for both vertical and horizontal forward and back adjustmentthereon.

16. An ophthalmological apparatus having, in combination, a pair orstationary members rigidly supported in substantially horizontalrelation, a pair of slides guided respectively for sliding movement onsaid members and each slide carrying a longitudinal series of prisms anyone oi which may be brought into the line ot sight of the eye at thatside, a pair of indejiiendently rotatable discs mounted respectivelyupon said members and each carrying an arcuate series of prisms any oneof Which may be brought into the line of sight to cooperate with one ofthe prisms on the slide, a base forming a rigid trame provided ivith atubular standard,a tubular internally screw-threaded stem telescopinginto the standard, means `for rigidly supporting said members upon theupper end of said stem, and a manuaily rotatable screw journaled at itslovver end in the iirame and threaded into said stem tor verticallyadjusting said members together with the parts carried thereby.

17. An ephthalmological apparatus having, in combination, a support, amanually rotatable disc mounted on the support carrying an arcuateseries of prisms any one of which may be brought into the line ot sight,rotatable holders for mounting a plurality oi the prisms on the disc toprovi de for axially rotating these prisms on the disc, a gear earriedby each oli' these holders, a manually rotatable master gear engagingall of' the holder gears, and releasable means tor holding the mastergear stationary at a plurality of rotative positions thereof, wherebysaid rotatable prisms Will be axially rotated when the disc is rotatedand also when the master gear is rotated thereby to bring these prismsto a desired axial position at the line oi'f sight.

18. An ophthalmologieal apparatus having, in combination, a base forminga rigid. :trame provided with a front and a rear standard, a pair otstationary members mounted upon the rear standard tor unitary verticaladjustment and individual lateral adjustment, a pair ot slides guidedrespectively -for independent sliding movement on said members and eachslide carrying a longitudinal series of prisms any one of which may bebrought into the line et sight ot the eye at that side, a pair otindependently rotatable discs mounted respectively7 upon said membersand each carrying an arcuate series of prisms any one of which may bebrought into the line or' sight to cooperate with one of the prisms inthe slide, a substantially horizontal rod mounted upon the lrontstandard for vertical adjustment and arranged in a vertical planeextending between the lines ot sight provided by said members. and achart holder projecting above and slidable along said rod.

19. An ophthalmological apparatus having, in combination, a support, aslide guided mas-,esc

on the support carrying a longitudinal series oit prisms progressivelyincreasing in prism power through the series and any one of which may bebrought into the line of sight, a rotatable disc mounted on the supportcarrying an arcuate series of prisms progressively increasing in prismpower through the series and any one oi which may be brought into theline ot sight to cooperate with one` of the prisms in the slide, meansfor mounting a plurality ot' the successive prisms on the disc toprovide tor their axial rotative movement thereon, and means iorconcomitantly axially rotating these prisms in unison in the samedirection at the same rate and setting them to different axial positionson the disc at the line of sight and relatively thereto.

20. An ophthalmological apparatus having, in combination, a pair ot'stationary members igidly supported in substantially horizontalrelation, a pair of slides guided respectively for sliding movement onsaid members and each slide carrying a longitudinal series of prisms anyone of which may be brought into the line of sightof the eye at thatside, a pair of independently rotatable discs mounted respectively uponsaid members and each carrying an arcuate series of prisms any one ofwhich may be brought into the line of sight to cooperate with oneu ofthe prisms in the slide, a rigid main support, a head rigidly carriedthereby, a pair of lateral arms rigidly projecting from the head andupon the outer ends of which said members respectively are rigidlycarried, and manually operable means engaging said head and arms formoving these arms together with the parts carried thereby simultaneouslyin opposite directions horizontally for there-` by varying the pupillarydistance apart of the lines of sight provided by said members throughsaid prisms.

21. An ophthalmological apparatus having, in combination, a pair ofstationary members rigidly supported in substantially horizontalrelation, a pair of slides guided respectively for sliding movement onsaid members and each slide carrying a longitudinal series of prisms anyone ot which may be brought into the line ot sight of the eye at thatside, a pair of independently rotatable discs mounted respectively uponsaid members and each carrying an arcuate series of prisms any one ofwhich may be brought into the line ot sight to cooperate with one ot theprisms in the slide, a base forming a rigid frame provided with astandard, a head rigidly carried by the top ot the standard, a pair ofhorizontal guide rods rigidly carried by the head and each projectinglaterally at opposite sides thereof in parallel relation, a pair oflateral upstanding arms the lower ends of which are supported and guidedupon said guide rods and upon the upper ends of which said membersrespectively are rigidly carried, and a horizont-al manually rotatablescrew journaled in said head and provided towards one end with righthandthreads engaging in one of said arms and provided towards its otherendwith leithand threads engaging in the other ot said arms for movingthese arms together `with the parts carried thereby simultaneously inopposite directions horizontally for thereby varying the pupillarydistance apart of the lines of sight provided by said members throughsaid prisms.

2Q. The invention delined in claim 2Q, in combination with meansproviding ior the vertical adjustment relatively to* the said mainsupport of said head together with the parts carried thereby.

23. An ophthalmologieal apparatus having, in combination, a pair ofstationary members rigidly supported `in substantialiy horizontalrelation, a pair of slides guided respectively for sliding movement onsaid members and each slide carrying a longiriir dinal series oi prismsany one ot which may be brought into the line oi' sight ot the eye atthat side, a pair ot' independently re tatable discs. mountedrespectively upon said members andeach carrying an `arcuate series oitprisms any one of which may be brought into the line oi sight to`cooperate with one of the prisms on the slide, a base forming a rigidframe provided with a tubular standard, a screw-threaded stemtelescoping into the standard, means tor rigidly supporting said members`upon the upper end of said stem, and a manually rotatable screwjournaled in the frame rand having threaded engagement with said stemfor vertically adjusting said members together with the parts carriedthereby. u 24.. An ophthalmological apparatus having, in combination, abase forming a rigid frame provided with a standard, a pair otstationary mem-bers mounted upon the standard for unitary verticaladjustment and individual lateral adjustment, a Vpair of slides guided`respectively for independent sliding` movement on said members and eachslide carrying longitudinal series ot prisms any one of whichmay bebrought into the linie of sigljit of `the eye at that side, and `a `pairof independently rotatable `discs mounted respectively upon, saidmembers and each carrying an arcuate series ot prisms any one of whichmay be brought into theline o'f'sight tocooperate with one of the prismsin the slide.

25, On ophthalmological apparatus havmg, in combination, a rigidsupporting member, a prism carrier movably mounted on the supportingmember carrying a series of prisms of iiXed value progressivelyincreasing in steps of prism power through the series and which may bebrought successively into the line of sight by the movement ofthecarrier to cooperate With a selected prism on a second prism carrier,and a second vprism carrier movably mounted on the supporting membercarrying a series or prisms of fixed value progressively mcreasing inVsteps of prism power through the series and which may be broughtsuccessively` into the line of sight by the movement of thev secondcarrier to cooperate with a selected prism on the'other prism carrier,in combination with means providing for concomitantly reversing theposition of the bases and apices of theV prisms in one of the saidseries relatively to the said supporting member, and means providing forconcomitantly reversing the position of the bases and apices ofthe'prsms in the other p said series relatively to the said supportingmember.

26. An ophthalmological apparatus having, in combination, a rigidlysupported stationary plate provided with a sight openinga slide rigidlycarrying a longitudinal series of prisms, a guide bracket for the slidehaving on its back a circular shoulder'passing through the sight.opening and by which the slide is pivotably mounted on the plate on anaxis coincident with the sight opening, radial lugs on the inner end ofthe .said shoulder for engagement with the inner side of the plate tohold the guide thereon, the sight opening in the plate being providedwith notches for the passage of said lugs to permit the removal andreplacement of the Guide bracket upon rotative movement thereo, anda setscrew carried by the guide bracket tobe setup against the said plate forholding the guide bracket and thus the slide atdifferent angularpositions.

27. An o hthalmological apparatus havn ing, in com ination, a rigid mainsupport,

a pair of stationary members mounted upon Y the main support for unitaryvertical adl series of prisms any one of which may be my signature.

justment and individual lateraladjustment, a pair of shdes 'guidedrespectively for independent sliding movement on said members and eachslide` carrying a longitudinal series ofprisms any one of which may beAVbrought into A,the line of sight of the eye at-that sidefand va pair ofindependently Vrotatable discs -mounted respectively upon said membersand each carryingan arcuate brought into the linel of sight to cooperateWith one of the prisms in the slide.

' In witness whereof, I hereunto subscribe "1 HANS CLEMENT.

